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Absolutely stunned at overall MPG with the new 2021 Prime!

Discussion in 'Prime Fuel Economy & EV Range' started by Thebakerman, Apr 2, 2021.

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  1. Thebakerman

    Thebakerman Member

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    I'm just amazed at how she gets 20MPG better minimum then any regular prius I've ever owned period! I was getting 82.5 MPG last night over 165 miles. Getting better at using the system vs regular prius. Anyone have any tips besides laying off throttle, or hypermiling which I'm basically already doing to get better MPG. Like in regards to using the hybrid system in a better way then auto etc?? What I have done is use auto up to about 10-15 percent left and then shut it off. The reason I do this, is to leave a little juice in the lithium battery to recharge via regen braking and gives me a little more power and while lot more "coast action" to get around town. What I can tell you, I was averaging around 70-72 depleting battery fully but now I have increased that by 10MPG by doing just that as described above!!

    Anyone else care to chime in for some help on more MPG using the 2 batteries and engine all together for say drives 150-250 miles trips daily. Or am I already getting the most??? I got 82 MPG yesterday over 180 miles just one charge for the duration Check pictures....thanks guys!!! 20210321_131324.jpeg 20210402_095748.jpeg 20210402_095240.jpeg 20210402_101111.jpeg 20210401_233609.jpeg

    Posted via the PriusChat mobile app.
     
    #1 Thebakerman, Apr 2, 2021
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  2. bisco

    bisco cookie crumbler

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    82mpg without ever plugging in?(n)
     
    #2 bisco, Apr 2, 2021
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  3. Salamander_King

    Salamander_King Senior Member

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    With the charge in the traction battery and driving EV mode, the displayed MPG is inflated. Unfortunately, on PP, there isn't an easy way to record real mpg in HV mode. The only reliable way is to drive without charge on HV mode only for a full tank and do the hand calculation of gallons of gas used and distance driven on HV mode only.
     
    #3 Salamander_King, Apr 2, 2021
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  4. Thebakerman

    Thebakerman Member

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    Without plugging it in and saving a reserve on main lithium I can get 70mpg. I would consider myself a 8 of 10 in "driving a prius" others could do better. I will over time. That's for sure. One plug in per day cost about 1.80 for about 30miles of ev. However if use all the ev up, you won't get the added benefit over long drives about 70-72MPG. I just found this out and boasted 10MPG with changing anything and just keeping 10-20 percent of ev to assist in uphills full ev mode and the best part is that the regenerative braking actually charges the 2nd "lithium battery as well" which I had no clue. I had 3 regular prius and nothing compares to this light sipper. My fuel cost are around 10 bucks max a day! Around 180-220 miles daily commute. All different driving as I drive all over southern California. Everyday is a different route. So at first I was like "it was just a lucky, mostly coasting route". Then over the last almost 2 weeks it has been the same. I'm like ok, I can get used to this! If you just charge the EV FULL and use eco mode (NO EV or EV Auto) you can expect 68-72mpg and only have to charge it once a week depending on driving habits and distances. You have to turn it off everytime you start the car as it turns on automatically. But I'm amazed at what I've got out of her so far! Amazing!

    Posted via the PriusChat mobile app.
     
    #4 Thebakerman, Apr 2, 2021
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  5. Thebakerman

    Thebakerman Member

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    Please also note that gas is $3.80 a gallon here! Also please note I have done the math! I used 2.23 gallons over the course of day and racked up 187 miles. The gas cost me $8.47. The FULL charge cost me $1.60. THIS EQUALS $10.07 TOTAL COST! Just say electric cost (Full Charge) being the cost of a 1/2 gallon of gas. Make that 2.63 instead of 2.23gallons of cost. Comes to 71.1 MPG. Dash reading gave 72.8. I've don't this twice with similar results. Give or take 2 miles . I'm going to do it again today. Plus a couple more times to make numbers stay accurate. However this is real world numbers and simple math!

    Posted via the PriusChat mobile app.
     
    #5 Thebakerman, Apr 2, 2021
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  6. Thebakerman

    Thebakerman Member

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    Actually there is and while it may not be exact, it is one hell of a rounded number of total cost divided by miles with gallons used. Check my other comment. Fortunately thanks to me there is a way. Can a get some like on this forum from a big member like yourself. Like a plaid or something. Just a starting out here. Thanks.
    Posted via the PriusChat mobile app.
     
    #6 Thebakerman, Apr 2, 2021
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  7. Salamander_King

    Salamander_King Senior Member

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    I am not following your math here. But in any way you calculate it, the number displayed on the dash is off by 5-8% on the optimistic side as all other Prius of earlier generation did. Still, it is easy to get 60+mpg on any of Gen4 Prius, and on PP, 70+mpg on pure HV only drive calculated is very doable.
     
    #7 Salamander_King, Apr 2, 2021
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  8. Thebakerman

    Thebakerman Member

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    Yes it is off, but not by 10-15 percent downside as earlier mentioned. We are talking less the 3 percent for accuracy. Pretty darn good to me! But for the record there is a simply way to calculate as stated above. Cost of gallon, gallons used, total miles used. That's it

    Ok gas used is 2.23 gallons ($3.80 per gal) used which cost about $8.47 cents plus ev charge of 1.60 to charge full. Just say 10.50 cents total cost divided by 187 total miles driven . That's the math.
     
    #8 Thebakerman, Apr 2, 2021
    Last edited by a moderator: Apr 3, 2021
  9. Salamander_King

    Salamander_King Senior Member

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    Where did you get a 10-15 percent downside? Empirically, all Prius models including Prius Prime display the mpg on dash 5-8% better than really is. You are saying the discrepancy is less than 3 percent but compared to what? Since the real mpg (HV only no EV mode used) is not displayed on the dash, if you drive any portion of the trip in EV mode with charge in the traction battery, the number is off. More you drive in EV mode more inflated the number will be with the upper limit of 999.9 mpg. There was a thread someone posted over 500mpg on the dash for a full tank of gas which is over 5000 miles on the trip meter since the last fill-up. Furthermore, the EV range from the charge is highly variable depending on how, where, and when you drive, so it is not simple to estimate the distance traveled by the EV mode. Yes, one can calculate the overall average cost/mile if you keep track of the amount of electricity used to charge the traction battery and the amount of gas you pumped into the tank. But that still will not give you the real mpg in HV mode. If you are only interested in true cost/mile, then that is a different story.
     
    #9 Salamander_King, Apr 2, 2021
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  10. Thebakerman

    Thebakerman Member

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    Well said. I'm talking about total cost including regenerative braking. The total overall cost MPG with MPGE factored. It's really pin point on MPG where I've seen other cars 10-15 percent.
     
    #10 Thebakerman, Apr 2, 2021
    Last edited by a moderator: Apr 3, 2021
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  11. bisco

    bisco cookie crumbler

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    what is the 2nd lithium battery?
     
    #11 bisco, Apr 2, 2021
  12. Thebakerman

    Thebakerman Member

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    How about the only lithium battery. Oopsie. Meant the 2nd battery which is lithium. LoL
     
    #12 Thebakerman, Apr 2, 2021
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  13. Tideland Prius

    Tideland Prius Moderator of the North
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    Well If you can charge up part of the battery, that'll boost your mpg.

    Note that the first hour charges up much more of the battery than the second hour. So if the public charging station charges by the hour, just plug for 1 hour or less. On an "empty" battery (so in HV mode), you'll get about 60% back. That's good for 15-20 miles depending on your efficiency. (or even 25 miles if it's warm outside with no A/C use). But it has to cost about $1/hr. If it's more, it's cheaper to run in hybrid mode and use gas.
     
    #13 Tideland Prius, Apr 3, 2021
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  14. Thebakerman

    Thebakerman Member

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    Yes this totally makes sense. Thank you!!
     
    #14 Thebakerman, Apr 3, 2021
  15. sam spade 2

    sam spade 2 Senior Member

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    I don't understand that statement at all.
    The displayed figure is TOTAL miles divided by the amount of gas burned.
    The total miles includes electric only and electric aided miles.
    Thus the higher figure.
    Isn't that why you got a Prime in the first place ??
     
    #15 sam spade 2, Apr 3, 2021
  16. bisco

    bisco cookie crumbler

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    when i first got my pip, after the thrill of ev died down a bit, i ran a couple tanks without plugging in to see what she delivered for actual mpg.
    it was about 10mpg over my 2008. never had a gen 3, so i couldn't compare.
     
    #16 bisco, Apr 3, 2021
  17. Banksy

    Banksy Active Member

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    My 08 averaged about 48

    In the summer on long trips 52

    I'm on screen aging 63 without EV

    That being said I'm only due to get high 500s on this tank

    Perhaps my avg when first getting the car was lower resulting in this

    Dash says 63 though
     
    #17 Banksy, Apr 3, 2021
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  18. bisco

    bisco cookie crumbler

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    63 seems reasonable, all depends on the climate and driving. will be interesting when you start with a reset and full tank, then refill.
     
    #18 bisco, Apr 3, 2021
  19. Thebakerman

    Thebakerman Member

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    Well of course especially when I drive 200 miles a day avg. It's a no brainer. The thing I didn't know is how much better MPG would be. In my 2010 I traded in with 180k was getting 42-46 depending on ac usage. Still good but when I'm paying a little less to charge and the same amount for gas but getting on avg now 30mpg is crazy surprised. Not to mention the HV stickers coming that I applied for. Didn't know until after the purchase. I kinda wish I wouldn't have bought the 2020 Limited regular prius cause the prime is so much better overall. Only exception is cargo space which can be rectified by a rack but then I guess you lose MpG on that as well. Well now I have 2 priuses 2020, 2021. I'm content, obviously. Lol
     
    #19 Thebakerman, Apr 4, 2021
  20. pakitt

    pakitt Senior Member

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    Averaging 999.9 MPG for 30 mi in EV mode before driving the rest of the 165 mi at xx MPG makes a noticeable difference.
    The more miles driven after the battery has been depleted, the more asymptotically the average MPG will reach the gas MPG done when driving in HV the rest of the way.

    I don't think that saving 10-15% charge, before switching to HV mode only, makes much difference. I think that when you switch to HV mode, whatever the charge in the "EV only" portion of the battery is left will not be used. And, unless you go down a really long slope and regain so much that the "HV mode" portion of the battery is full, only then the extra regen energy goes the rest of the battery.

    There is only one battery in the Prime, and the allotment is virtual. The computer simply decides how much battery charge to reserve to each mode. When in HV you can use only a fraction of the battery, but charge up more if you can regain enough. In the regular Prius that extra regain would go wasted in heat by pumping air in the ICE (i.e., ICE braking.) Instead in EV mode only, you can use all of the battery, except the HV portion, that is, when you reach 0%. At that point there is still enough battery charge saved to initiate HV mode (warming up the ICE while still pushing the car electrically) and after 2mi or so (or whatever the range was/is on the Gen4 in EV mode - I forget now,) the ICE needs to kick-in and push the car, regardless of warming stage reached.

    I am pretty sure that in EV Auto mode, the ICE gets warmed up well before the EV mode portion of the battery reaches 0% (I have seen it revving up at 10-15%.) This is why I would like to be able to set as default mode EV Auto, rather than EV mode. Too bad this is not a user setting and gets reset each time you turn on the car. (unless somebody on PriusChat knows how to set the car in EV Auto at startup.)
     
    #20 pakitt, May 25, 2021
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